/* * CDDL HEADER START * * The contents of this file are subject to the terms of the * Common Development and Distribution License (the "License"). * You may not use this file except in compliance with the License. * * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE * or http://www.opensolaris.org/os/licensing. * See the License for the specific language governing permissions * and limitations under the License. * * When distributing Covered Code, include this CDDL HEADER in each * file and include the License file at usr/src/OPENSOLARIS.LICENSE. * If applicable, add the following below this CDDL HEADER, with the * fields enclosed by brackets "[]" replaced with your own identifying * information: Portions Copyright [yyyy] [name of copyright owner] * * CDDL HEADER END */ /* * Copyright 2009 Sun Microsystems, Inc. All rights reserved. * Use is subject to license terms. */ /* * Copyright (c) 2012, 2015 by Delphix. All rights reserved. */ #ifndef _ZIO_IMPL_H #define _ZIO_IMPL_H #include <sys/zfs_context.h> #include <sys/zio.h> #ifdef __cplusplus extern "C" { #endif /* * XXX -- Describe ZFS I/O pipeline here. Fill in as needed. * * The ZFS I/O pipeline is comprised of various stages which are defined * in the zio_stage enum below. The individual stages are used to construct * these basic I/O operations: Read, Write, Free, Claim, and Ioctl. * * I/O operations: (XXX - provide detail for each of the operations) * * Read: * Write: * Free: * Claim: * Ioctl: * * Although the most common pipeline are used by the basic I/O operations * above, there are some helper pipelines (one could consider them * sub-pipelines) which are used internally by the ZIO module and are * explained below: * * Interlock Pipeline: * The interlock pipeline is the most basic pipeline and is used by all * of the I/O operations. The interlock pipeline does not perform any I/O * and is used to coordinate the dependencies between I/Os that are being * issued (i.e. the parent/child relationship). * * Vdev child Pipeline: * The vdev child pipeline is responsible for performing the physical I/O. * It is in this pipeline where the I/O are queued and possibly cached. * * In addition to performing I/O, the pipeline is also responsible for * data transformations. The transformations performed are based on the * specific properties that user may have selected and modify the * behavior of the pipeline. Examples of supported transformations are * compression, dedup, and nop writes. Transformations will either modify * the data or the pipeline. This list below further describes each of * the supported transformations: * * Compression: * ZFS supports three different flavors of compression -- gzip, lzjb, and * zle. Compression occurs as part of the write pipeline and is performed * in the ZIO_STAGE_WRITE_BP_INIT stage. * * Dedup: * Dedup reads are handled by the ZIO_STAGE_DDT_READ_START and * ZIO_STAGE_DDT_READ_DONE stages. These stages are added to an existing * read pipeline if the dedup bit is set on the block pointer. * Writing a dedup block is performed by the ZIO_STAGE_DDT_WRITE stage * and added to a write pipeline if a user has enabled dedup on that * particular dataset. * * NOP Write: * The NOP write feature is performed by the ZIO_STAGE_NOP_WRITE stage * and is added to an existing write pipeline if a crypographically * secure checksum (i.e. SHA256) is enabled and compression is turned on. * The NOP write stage will compare the checksums of the current data * on-disk (level-0 blocks only) and the data that is currently being written. * If the checksum values are identical then the pipeline is converted to * an interlock pipeline skipping block allocation and bypassing the * physical I/O. The nop write feature can handle writes in either * syncing or open context (i.e. zil writes) and as a result is mutually * exclusive with dedup. * * Encryption: * Encryption and authentication is handled by the ZIO_STAGE_ENCRYPT stage. * This stage determines how the encryption metadata is stored in the bp. * Decryption and MAC verification is performed during zio_decrypt() as a * transform callback. Encryption is mutually exclusive with nopwrite, because * blocks with the same plaintext will be encrypted with different salts and * IV's (if dedup is off), and therefore have different ciphertexts. For dedup * blocks we deterministically generate the IV and salt by performing an HMAC * of the plaintext, which is computationally expensive, but allows us to keep * support for encrypted dedup. See the block comment in zio_crypt.c for * details. */ /* * zio pipeline stage definitions */ enum zio_stage { ZIO_STAGE_OPEN = 1 << 0, /* RWFCI */ ZIO_STAGE_READ_BP_INIT = 1 << 1, /* R---- */ ZIO_STAGE_WRITE_BP_INIT = 1 << 2, /* -W--- */ ZIO_STAGE_FREE_BP_INIT = 1 << 3, /* --F-- */ ZIO_STAGE_ISSUE_ASYNC = 1 << 4, /* RWF-- */ ZIO_STAGE_WRITE_COMPRESS = 1 << 5, /* -W--- */ ZIO_STAGE_ENCRYPT = 1 << 6, /* -W--- */ ZIO_STAGE_CHECKSUM_GENERATE = 1 << 7, /* -W--- */ ZIO_STAGE_NOP_WRITE = 1 << 8, /* -W--- */ ZIO_STAGE_DDT_READ_START = 1 << 9, /* R---- */ ZIO_STAGE_DDT_READ_DONE = 1 << 10, /* R---- */ ZIO_STAGE_DDT_WRITE = 1 << 11, /* -W--- */ ZIO_STAGE_DDT_FREE = 1 << 12, /* --F-- */ ZIO_STAGE_GANG_ASSEMBLE = 1 << 13, /* RWFC- */ ZIO_STAGE_GANG_ISSUE = 1 << 14, /* RWFC- */ ZIO_STAGE_DVA_THROTTLE = 1 << 15, /* -W--- */ ZIO_STAGE_DVA_ALLOCATE = 1 << 16, /* -W--- */ ZIO_STAGE_DVA_FREE = 1 << 17, /* --F-- */ ZIO_STAGE_DVA_CLAIM = 1 << 18, /* ---C- */ ZIO_STAGE_READY = 1 << 19, /* RWFCI */ ZIO_STAGE_VDEV_IO_START = 1 << 20, /* RW--I */ ZIO_STAGE_VDEV_IO_DONE = 1 << 21, /* RW--I */ ZIO_STAGE_VDEV_IO_ASSESS = 1 << 22, /* RW--I */ ZIO_STAGE_CHECKSUM_VERIFY = 1 << 23, /* R---- */ ZIO_STAGE_DONE = 1 << 24 /* RWFCI */ }; #define ZIO_INTERLOCK_STAGES \ (ZIO_STAGE_READY | \ ZIO_STAGE_DONE) #define ZIO_INTERLOCK_PIPELINE \ ZIO_INTERLOCK_STAGES #define ZIO_VDEV_IO_STAGES \ (ZIO_STAGE_VDEV_IO_START | \ ZIO_STAGE_VDEV_IO_DONE | \ ZIO_STAGE_VDEV_IO_ASSESS) #define ZIO_VDEV_CHILD_PIPELINE \ (ZIO_VDEV_IO_STAGES | \ ZIO_STAGE_DONE) #define ZIO_READ_COMMON_STAGES \ (ZIO_INTERLOCK_STAGES | \ ZIO_VDEV_IO_STAGES | \ ZIO_STAGE_CHECKSUM_VERIFY) #define ZIO_READ_PHYS_PIPELINE \ ZIO_READ_COMMON_STAGES #define ZIO_READ_PIPELINE \ (ZIO_READ_COMMON_STAGES | \ ZIO_STAGE_READ_BP_INIT) #define ZIO_DDT_CHILD_READ_PIPELINE \ ZIO_READ_COMMON_STAGES #define ZIO_DDT_READ_PIPELINE \ (ZIO_INTERLOCK_STAGES | \ ZIO_STAGE_READ_BP_INIT | \ ZIO_STAGE_DDT_READ_START | \ ZIO_STAGE_DDT_READ_DONE) #define ZIO_WRITE_COMMON_STAGES \ (ZIO_INTERLOCK_STAGES | \ ZIO_VDEV_IO_STAGES | \ ZIO_STAGE_ISSUE_ASYNC | \ ZIO_STAGE_CHECKSUM_GENERATE) #define ZIO_WRITE_PHYS_PIPELINE \ ZIO_WRITE_COMMON_STAGES #define ZIO_REWRITE_PIPELINE \ (ZIO_WRITE_COMMON_STAGES | \ ZIO_STAGE_WRITE_COMPRESS | \ ZIO_STAGE_ENCRYPT | \ ZIO_STAGE_WRITE_BP_INIT) #define ZIO_WRITE_PIPELINE \ (ZIO_WRITE_COMMON_STAGES | \ ZIO_STAGE_WRITE_BP_INIT | \ ZIO_STAGE_WRITE_COMPRESS | \ ZIO_STAGE_ENCRYPT | \ ZIO_STAGE_DVA_THROTTLE | \ ZIO_STAGE_DVA_ALLOCATE) #define ZIO_DDT_CHILD_WRITE_PIPELINE \ (ZIO_INTERLOCK_STAGES | \ ZIO_VDEV_IO_STAGES | \ ZIO_STAGE_DVA_THROTTLE | \ ZIO_STAGE_DVA_ALLOCATE) #define ZIO_DDT_WRITE_PIPELINE \ (ZIO_INTERLOCK_STAGES | \ ZIO_STAGE_WRITE_BP_INIT | \ ZIO_STAGE_ISSUE_ASYNC | \ ZIO_STAGE_WRITE_COMPRESS | \ ZIO_STAGE_ENCRYPT | \ ZIO_STAGE_CHECKSUM_GENERATE | \ ZIO_STAGE_DDT_WRITE) #define ZIO_GANG_STAGES \ (ZIO_STAGE_GANG_ASSEMBLE | \ ZIO_STAGE_GANG_ISSUE) #define ZIO_FREE_PIPELINE \ (ZIO_INTERLOCK_STAGES | \ ZIO_STAGE_FREE_BP_INIT | \ ZIO_STAGE_DVA_FREE) #define ZIO_DDT_FREE_PIPELINE \ (ZIO_INTERLOCK_STAGES | \ ZIO_STAGE_FREE_BP_INIT | \ ZIO_STAGE_ISSUE_ASYNC | \ ZIO_STAGE_DDT_FREE) #define ZIO_CLAIM_PIPELINE \ (ZIO_INTERLOCK_STAGES | \ ZIO_STAGE_DVA_CLAIM) #define ZIO_IOCTL_PIPELINE \ (ZIO_INTERLOCK_STAGES | \ ZIO_STAGE_VDEV_IO_START | \ ZIO_STAGE_VDEV_IO_ASSESS) #define ZIO_TRIM_PIPELINE \ (ZIO_INTERLOCK_STAGES | \ ZIO_STAGE_ISSUE_ASYNC | \ ZIO_VDEV_IO_STAGES) #define ZIO_BLOCKING_STAGES \ (ZIO_STAGE_DVA_ALLOCATE | \ ZIO_STAGE_DVA_CLAIM | \ ZIO_STAGE_VDEV_IO_START) extern void zio_inject_init(void); extern void zio_inject_fini(void); #ifdef __cplusplus } #endif #endif /* _ZIO_IMPL_H */
